与不断提升的计算能力相适应,移动手持设备上的存储系统结构越来越复杂,容量越来越大.这种趋势导致存储系统,主要是片上缓存和主存,在系统总能耗的占比中不断攀升.在当前手持设备多由电池驱动并且电池容量十分有限的情况下。存储系统的低功耗设计就显得十分重要.虽然现有的存储器件提供了一定的硬件节能支持,但是只有与应用程序的访存行为的规律相结合,才能充分发挥硬件的节能潜力.对现有的各种低功耗存储技术进行了梳理和总结,给出程序的访存模式的概念,归纳出访存模式在3个方面的内涵,并进一步详细介绍了程序的访存模式在片上缓存和主存低功耗技术中的应用.最后,展望未来结合访存模式进行低功耗存储系统研发的可能方向.
To keep pace with the fast growing computing power, the memory system of mobile devices has become more complicated and larger in capacity. As a result, the memory systems, especially the on-chip cache and the main memory, consume a major portion of the system energy. With the limited lifespan of the battery, the memory system of the mobile device demands energy-efficient design and techniques urgently. Without the exploration of the memory access patterns of the programs, it is impossible to fully exploit the potential energy benefits provided by the current memory hardware. This paper introduces the memory access patterns of the programs, describes its three main characteristics, and discusses how to develop energy-efficient techniques based on it in detail. In the end, some future trends in this area are discussed.